JP5606972B2 - Slewing bearing seal structure and slewing bearing - Google Patents

Description

  The present invention is, for example, a swivel used for a swivel part of various machines used in the vicinity of the outdoors or indoors, such as a swivel seat for a yaw and a blade of a wind power generator, a deck crane, a construction machine, and a lifting machine. The present invention relates to a seal structure of a bearing and a slewing bearing.

  A swivel bearing used for a yaw of a wind power generator, a swivel seat for a blade, or the like is generally lubricated with grease. This slewing bearing is provided with a rubber seal in order to prevent foreign matters from entering from outside or grease leakage from inside the bearing (Patent Documents 1 and 2). Nitrile, chloroprene, acrylic, etc. are used as the material of this rubber.

JP-A-7-310645 German utility model No. 20203372 specification

  In particular, a rubber seal used for a slewing bearing for a yaw and blade of a wind power generation apparatus has an important function of preventing grease leakage from the viewpoint of protecting the surrounding environment. Since the slewing bearing is generally operated at a low speed, there is little problem of heat generation. However, as shown in FIG. 9, when additional grease is supplied from the grease supply pipe 50, the pressure inside the bearing rises. As shown in the drawing, the grease supply pipe 50 is a pipe that penetrates in the radial direction from the outer ring outer diameter surface or the inner ring inner diameter surface toward the inside of the bearing. As described above, since the pressure inside the bearing rises, the internal pressure acts on the rubber seal portion 51.

When the internal pressure generated in the rubber seal portion 51 is large, the seal lip 52 may be reversed or fall off from the seal fixing portion. The direction of the seal lip 52 is two patterns: an inward lip 52a extending inwardly in the axial direction of the bearing space toward the tip, and an outward lip 52b extending inclining outward in the axial direction of the bearing space toward the tip. is there.
In order to withstand the internal pressure, an inward lip 52a is required. However, if the inward lip 52a is subjected to a pressure higher than expected, there is a problem that the lip is inverted. As a means for preventing the problem, it is conceivable to increase the lip rigidity by increasing the thickness of the lip. However, if the thickness of the lip is increased, the sealing torque increases, which may affect the specifications of the drive device, that is, it may be necessary to increase the capacity of the turning torque.

  An object of the present invention is to provide a seal structure for a slewing bearing and a slewing bearing that can prevent the lip portion of the seal member from being reversed and the seal member from falling off when the internal pressure is increased, and can reduce the seal torque. .

The seal structure of the slewing bearing of this invention is
A raceway groove is formed in each of the races of the inner ring and the outer ring, a plurality of rolling elements are provided between the raceway grooves of the inner and outer rings, and a step which becomes uneven between the inner and outer rings is provided at the axial end of the inner and outer rings. In the seal structure of the slewing bearing provided with the seal member made of an elastic body that seals the axial ends of the inner and outer rings having the step,
The seal member includes a base fixed to a portion protruding from the concave raceway of the convex raceway that is the convex side of the step, and one or more that are in contact with the concave raceway that is the concave side of the step. A lip portion, and one of the lip portions includes a main lip that extends in an inclined manner so as to be located on the inner side in the axial direction of the bearing space toward the tip.
Provided on the peripheral surface of the concave raceway on the bearing space side is a seal slidable contact portion for slidingly contacting the main lip of the seal member, and on the end side of the peripheral surface of the concave raceway than the seal slidable contact portion. The annular projecting portion projecting in the radial direction is provided, and the seal sliding side inclined portion is disposed on the inner surface in the axial direction of the annular projecting portion so as to be located on the outer side in the axial direction toward the projecting tip.
An annular groove is provided on the peripheral surface of the convex raceway, and a fixing groove is provided on an outer surface in the axial direction at the bottom of the annular groove, and the base portion of the seal member includes the peripheral surface of the convex raceway and the circumferential surface. There is a groove for fitting into which the annular wall portion that is a portion between the inner surface of the fixed groove is fitted, and the groove side surface on the bearing space side of the inner surface of the fixed groove moves away from the bearing space toward the groove bottom side portion. A seal fixing side inclined portion that is inclined so as to be positioned on the side is provided.

According to this configuration, when internal pressure is applied to the seal member, the main lip is pressed against the seal sliding side inclined portion of the annular projection of the concave raceway, and the base is inclined to the seal fixing side of the convex raceway. Pressed against the part. That is, the main lip and the base of the seal member are both supported by the race ring. At this time, since the main lip and the base portion come into contact with the respective inclined portions facing each other, the inversion of the lip portion can be suppressed, and the seal member can be prevented from falling off the raceway. Accordingly, in order to prevent the lip portion from being reversed, it is not necessary to increase the lip rigidity by increasing the thickness of the lip portion. Therefore, the thickness of the lip portion can be made thinner than that of the conventional one, and the sealing torque can be reduced.
In addition, by inserting a part of the base portion of the seal member into the fixed groove provided on the peripheral surface of the convex raceway ring, the annular wall portion between the peripheral surface of the convex raceway ring and the inner surface of the fixed groove is Since the fitting member is fitted in the fitting groove, the seal member can be easily fixed to the convex race. Therefore, the number of assembly steps can be reduced. In this case, an adhesive or the like for fixing the seal member is not necessary, and other components such as a lid for suppressing the seal are also unnecessary, so that the number of components can be reduced and the manufacturing cost can be reduced. The workability when exchanging worn seal members is also greatly improved over the prior art.

Of the base portion of the seal member, the inner surface of the base portion facing the bottom of the annular groove of the convex raceway ring may have a shape connected by a single curved surface or a continuous curved surface having no inflection point.
Of the base portion of the seal member, the inner surface of the base portion facing the bottom portion of the annular groove of the convex raceway ring may be connected to a plurality of surfaces having intersection angles of 90 degrees or more and 180 degrees or less. The “intersection angle” refers to an angle viewed from the inside of the seal member.
In these cases, the rigidity of the base portion of the seal member can be increased and local deformation can be prevented.

  An angle of an intersection line connecting the axial inner side surface of the main lip and the base inner side surface of the base may be 180 degrees or more and 270 degrees or less. The “angle” refers to an angle viewed from the inside of the seal member. In this case, the main lip can be positively elastically deformed by applying an internal pressure to a portion connecting the axial inner side surface of the main lip and the base inner side surface of the base portion. Thereby, even if it is a case where the hooking amount of a base is small with respect to an annular wall part, it can prevent that the sealing member is pulled out by the base side.

  The seal slide is formed so that the surface of the annular protrusion extending from the seal sliding side inclined portion toward the convex raceway and the surface of the fixing groove extending from the seal fixing side inclined portion toward the concave raceway are crossed. A moving side inclined portion and a seal fixing side inclined portion may be provided. In this case, the surface where the seal sliding side inclined portion is extended to the convex bearing ring side and the surface where the seal fixing side inclined portion of the fixing groove is extended to the concave bearing ring side are brought close to one plane so that the sealing member When the internal pressure is applied, the main lip and the base of the seal member can be more reliably brought into contact with the surface.

  The main lip may be thinner than the base. In this case, the seal torque of the lip portion can be reduced, and the main lip can be positively elastically deformed when an internal pressure is applied to the seal member. As a result, the main lip is surely pressed against the seal sliding side inclined portion of the annular projection of the concave raceway, so that the sealing member can be used even when the hooking amount of the base portion is small relative to the annular wall portion. Can be prevented from coming out on the base side.

The seal member may be made of nitrile or chloroprene.
The seal member may include, as one of the lip portions, a sub lip branched from the base portion separately from the main lip and in contact with the end surface of the concave raceway. By this sub lip, the sealing performance of the sealing member is further maintained, and grease leakage from the bearing space can be prevented.

  The initial tightening allowance of the main lip may be 2 mm or more and 6 mm or less. By setting such an initial tightening allowance, it is possible to reduce the seal torque and prevent grease leakage from the bearing space.

  The bottom surface of the fitting groove of the seal base or the bearing space side groove side surface may be brought into contact with the seal base. As a result, the coefficient of friction is increased, the fixation of the seal base can be stabilized, and the suppression of grease leakage from the fixed part can be enhanced. Further, since the tightness of the seal lip can be maintained, the sealing performance can be stabilized.

The slewing bearing of the present invention is one in which any of the above-described seal structures is applied.
A wind turbine blade may be supported so as to be rotatable about an axis substantially perpendicular to the main shaft axis with respect to the main shaft.
The nacelle of the windmill may be supported so as to be rotatable with respect to the support base.

In the seal structure of the slewing bearing according to the present invention, a raceway groove is formed in each of the race rings of the inner ring and the outer ring, a plurality of rolling elements are provided between the race grooves of the inner and outer rings, and at the axial ends of the inner and outer rings, In the seal structure of the slewing bearing provided with a step that becomes uneven between the inner and outer rings, and provided with an elastic seal member that seals the axial end of the inner and outer rings having the step,
The seal member includes a base fixed to a portion protruding from the concave raceway of the convex raceway that is the convex side of the step, and one or more that are in contact with the concave raceway that is the concave side of the step. One of the lip portions includes a main lip that is inclined and extends inward in the axial direction of the bearing space toward the tip. Further, a seal sliding contact surface portion for slidingly contacting the main lip of the seal member is provided on the peripheral surface of the concave bearing ring on the bearing space side, and the end side is closer to the seal sliding contact portion on the peripheral surface of the concave bearing ring. An annular projecting portion projecting in the radial direction is provided on the inner surface in the axial direction of the annular projecting portion, and a seal sliding side inclined portion is disposed so as to be located on the outer side in the axial direction toward the projecting tip. An annular groove is provided on the peripheral surface of the side raceway, and a fixed groove is provided on an axially outer surface at the bottom of the annular groove, and the base portion of the seal member is formed by the peripheral surface and the fixed groove on the convex side raceway. A groove for fitting to be fitted into an annular wall portion that is a portion between the inner surface of the fixing groove, and on the groove side surface of the peripheral surface on the inner surface of the fixed groove, on the side away from the bearing space toward the groove bottom side portion. Seal fixing side that is inclined to be positioned Due to the provision of the oblique portion can be prevented from falling off the inverted and the seal member of the lip portion of the seal member during increase in the internal pressure, it is possible to reduce the sealing torque.

1 is a cross-sectional view of a slewing bearing according to a first embodiment of the present invention. (A) is sectional drawing which shows partially the sealing structure of the slewing bearing, etc., (B) is sectional drawing of the sealing member single-piece | unit of the sealing structure. It is sectional drawing which shows partially the seal structure of the slewing bearing, etc. which concern on other embodiment of this invention. It is sectional drawing which shows partially the seal structure of the slewing bearing, etc. which concern on further another embodiment of this invention. It is sectional drawing which shows partially the seal structure of the slewing bearing, etc. which concern on further another embodiment of this invention. It is sectional drawing which shows partially the seal structure of the slewing bearing, etc. which concern on further another embodiment of this invention. It is the perspective view which notched and represented a part of example of the wind power generator. It is a fracture side view of the wind power generator. It is sectional drawing of the slewing bearing of a prior art example, and its principal part.

  A seal structure for a slewing bearing according to a first embodiment of the present invention will be described with reference to FIGS. The following description also includes a description of the design method of the seal structure. This slewing bearing is, for example, a bearing that supports the blade of a wind turbine for wind power generation so that it can pivot about an axis substantially perpendicular to the main shaft axis or a nacelle of the wind turbine relative to a support base. Used as a bearing to support.

  As shown in FIG. 1, the slewing bearing is adjacent to the inner ring 1, the outer ring 2, and a plurality of balls 3 that are rotatably interposed between the raceway grooves 1 a and 2 a of the inner and outer rings 1 and 2. A spacer (not shown) interposed between the balls 3 and 3 and a seal member 5 described later are provided. Each of the raceway grooves 1a and 2a of the inner and outer rings 1 and 2 is composed of two curved surfaces. The two curved surfaces constituting each raceway groove 1a, 2a are Gothic arch-shaped arcs having a larger radius of curvature than the balls 3 as rolling elements and different curvature centers. Each ball 3 is in contact with the curved surfaces of the inner ring raceway groove 1a and the outer ring raceway groove 2a at a point of contact with each other at four points. This slewing bearing is configured as a four-point contact ball bearing. The spacer is made of, for example, a resin material, and the spacer has a concave shape in which the ball contact surfaces on both sides form a spherical surface that is deeply recessed toward the center.

  The outer ring 2 is provided with a plurality of through holes 2b at regular intervals in the circumferential direction. These through-holes 2b are used, for example, for connecting and fixing the outer ring 2 to a support base described later. The inner ring 1 is also provided with a plurality of through holes 1b at regular intervals in the circumferential direction. These through holes 1b are used, for example, for connecting and fixing the inner ring 1 to a casing of a nacelle, which will be described later. Each through-hole 1b, 2b is formed in parallel with the bearing axial direction.

The seal structure will be described.
As shown in FIG. 1, steps δ that are uneven between the inner and outer rings 1 and 2 are provided at the axial ends of the inner and outer rings 1 and 2, in this example, at both ends in the axial direction. The bearing space 4 of the inner and outer rings 1 and 2 is filled with grease, and the seal members 5 and 5 seal both axial ends of the inner and outer rings 1 and 2 having the step δ. The seal member 5 at one end in the axial direction (upper part in FIG. 1) will be described. In the upper seal member 5 of FIG. 1, the convex raceway that is the convex side of the step δ is the inner ring 1, and the concave raceway that is the concave side of the step δ is the outer ring 2.

  The seal member 5 is made of an elastic body such as nitrile or chloroprene, and has a base portion 6 and a lip portion 9 including a main lip 7 and a sub lip 8 as shown in FIG. The base portion 6 and the lip portion 9 are provided integrally. The base portion 6 includes a seal fixing portion 10 that is fixed to the inner ring 1 that is a convex raceway ring, and a seal body portion 11 that is connected to the seal fixing portion 10. A fitting groove 10 a is provided on the inner peripheral surface side of the seal fixing portion 10 of the base portion 6. The fitting groove 10a is formed so as to open annularly outward in the axial direction.

  The seal fixing portion 10 of the base portion 6 is fixed to a portion of the inner ring 1 that protrudes in the axial direction from the outer ring 2. An annular groove 12 is provided on the outer peripheral surface of the inner ring 1, and a fixing groove 13 is provided on the outer surface in the axial direction at the bottom of the annular groove 12. An annular wall portion 14, which is a portion between the outer peripheral surface and the inner surface of the fixed groove 13, is fitted into the fitting groove 10 a of the base portion 6. Further, on the groove side surface on the bearing space side on the inner surface of the fixed groove 13, there is provided a seal fixed side inclined portion 13 a that is inclined so as to be positioned on the outer side in the axial direction toward the groove bottom side portion. When the seal fixing part 10 is fixed to the inner ring 1, a part of the seal fixing part 10 abuts and is fixed to the seal fixing side inclined part 13 a, and the step part 1 c formed on the outer peripheral surface of the inner ring 1 is fixed. The other part of the seal fixing part 10 is engaged and fixed. Further, when an internal pressure is applied to the seal member 5, the part of the seal fixing portion 10 is pressed against the seal fixing side inclined portion 13a.

As shown in FIG. 2B, in the seal member alone before the seal fixing portion 10 is fixed to the inner ring 1, the maximum radial clearance δa between a part of the seal fixing portion 10 and another part. Is formed narrower than when the seal fixing portion 10 is fixed to the inner ring 1 (FIG. 2A). As shown in FIG. 2A, when the annular wall portion 14 of the inner ring 1 is fitted into the fitting groove 10a, the part of the seal fixing portion 10 is elastically deformed radially inward (in other words, For example, the seal fixing portion 10 is in contact with the seal fixing side inclined portion 13a (separated from the other part of the seal fixing portion 10). At the same time, the other part of the seal fixing portion 10 is engaged with the step portion 1 c of the inner ring 1.
The inner side surface 15 on the inner side in the axial direction at the bottom of the annular groove 12 is formed, for example, in parallel with the inclined surface of the seal fixing side inclined portion 13a, and the base portion 6 of the seal member 5 does not interfere with the inner side surface 15 and the groove bottom surface. It is provided as follows. Of the base 6 of the seal member 5, the base inner side surface 6 a facing the bottom of the annular groove 12 is formed as a shape connected with a single curved surface or a continuous curved surface having no inflection point, forming a curved surface inward in the radial direction. Yes.

  As shown in FIG. 2A, the main lip 7 of the lip portion 9 extends in an inclined manner so as to be positioned on the inner side in the axial direction of the bearing space toward the tip. The main lip 7 extends obliquely inward in the axial direction from the outer surface of the seal body 11 facing the inner peripheral surface of the outer ring of the seal body 11. A thickness t1 of the main lip 7 is provided thinner than a radial thickness t2 of the seal body 11 of the base 6. Of the seal body 11 of the base 6, the angle α1 of the line connecting the base inner surface 6a facing the bottom of the annular groove 12 and the axial inner surface 7a of the main lip 7 is 180 degrees or more and 270 degrees or less. . In this embodiment, since the base inner side surface 6a is connected by a single curved surface or a continuous curved surface having no inflection point, the tangent line La passing through the axial inner side surface of the main lip 7 of the base inner side surface 6a The angle α1 of the intersection line connecting the axially inner side surfaces of the main lip 7 is set as described above. The “angle” refers to an angle viewed from the inside of the seal member 5. The initial fastening allowance of the main lip 7 is set to 2 mm or more and 6 mm or less.

  A seal slidable contact surface portion 2c for slidably contacting the main lip 7 is provided on the outer ring inner peripheral surface on the bearing space side of the outer ring 2 which is a concave raceway. An annular projecting portion 16 projecting in the radial direction is provided on the inner peripheral surface of the outer ring on the end side of the seal sliding contact surface portion 2c. A seal sliding side inclined portion 16a that is inclined so as to be positioned on the outer side in the axial direction toward the protruding tip is provided on the inner surface in the axial direction facing the bearing space in the annular protruding portion 16. When an internal pressure is applied to the seal member 5, the main lip 7 is pressed against the seal sliding side inclined portion 16a. Further, the seal sliding side inclined portion is formed such that the surface S2 extending the seal sliding side inclined portion 16a toward the inner ring 1 and the surface S1 extending the seal fixing side inclined portion 13a of the fixing groove 13 toward the outer ring 2 intersect. 16a and a seal fixing side inclined portion 13a are provided.

  The auxiliary lip 8 of the lip portion 9 branches from the seal body portion 11 of the base portion 6 separately from the main lip 7 and comes into contact with the end surface 2 d of the outer ring 2. That is, the sub lip 8 extends in an axially inclining manner from the lower end surface portion of the seal body portion 11 facing the end surface 2d of the outer ring 2, and makes axial contact with the end surface 2d of the outer ring 2. The sub-lip 8 has a thickness t3 that is thinner than the axial thickness t4 of the seal body 11. The secondary lip 8 is also called a dust lip.

  As shown in FIG. 1, at the other axial end of the inner and outer rings 1 and 2 (lower part in FIG. 1), the convex raceway ring that is the convex side of the step δ is the outer ring 2 and the concave side of the step δ. The concave raceway is the inner ring 1. Since the seal structure provided at the other end in the axial direction is the same as the seal structure at one end in the axial direction, the same reference numerals as those assigned to the seal structure are attached and the description thereof is omitted.

  According to the seal structure of the slewing bearing described above, when the internal pressure is applied to the seal member 5, the main lip 7 is pressed against the seal sliding side inclined portion 16a of the annular protrusion 16 of the concave raceway, and the base portion 6 is pressed against the seal fixing side inclined portion 13a of the convex raceway. That is, the main lip 7 and the base 6 of the seal member 5 are both supported by the raceway ring. At this time, the main lip 7 and the base portion 6 come into contact with the respective inclined portions 16a and 13a facing each other, so that the inversion of the lip portion 9 can be suppressed and the seal member 5 is prevented from falling off the raceway. can do. Accordingly, in order to prevent the lip portion from being reversed, it is not necessary to increase the lip rigidity by increasing the thickness of the lip portion. Therefore, the thickness of the lip portion 9 can be made thinner than that of the conventional one, and the sealing torque can be reduced.

  Further, by inserting the base portion 6 of the seal member 5 into the fixed groove 13 provided on the peripheral surface of the convex raceway, the annular wall portion 14 between the peripheral surface of the convex raceway and the inner surface of the fixed groove 13 is Since it fits in the fitting groove 10a of the base 6, the seal member 5 can be easily fixed to the convex raceway. Therefore, the number of assembly steps can be reduced. In this case, an adhesive or the like for fixing the seal member 5 is not necessary, and other components such as a lid for suppressing the seal are also unnecessary, so that the number of components can be reduced and the manufacturing cost can be reduced. The workability when replacing the worn seal member 5 is also greatly improved as compared with the prior art.

Of the base 6 of the seal member 5, the base inner side surface 6 a facing the bottom of the annular groove 12 has a shape connected by a single curved surface or a continuous curved surface having no inflection point. The rigidity can be increased and local deformation can be prevented.
Since the angle α1 of the intersection line connecting the axial inner side surface 7a of the main lip 7 and the base inner side surface 6a of the base 6 is set to 180 degrees or more and 270 degrees or less, the axial inner side surface 7a of the main lip 7 and the base 6 The main lip 7 can be positively elastically deformed by applying an internal pressure to the portion P1 connecting the base inner side surface 6a. Thereby, even when the catching amount of the base portion 6 is small with respect to the annular wall portion 14, the seal member 5 can be prevented from coming out on the base portion 6 side.

  A surface S2 in which the seal sliding side inclined portion 16a of the annular protrusion 16 extends to the convex raceway side and a surface S1 in which the seal fixing side inclined portion 13a of the fixing groove 13 extends to the concave side of the raceway intersect. As described above, since the seal sliding side inclined portion 16a and the seal fixing side inclined portion 13a are provided, the following effects can be obtained. A surface S2 obtained by extending the seal sliding side inclined portion 16a toward the convex raceway ring and a surface S1 obtained by extending the seal fixing side inclined portion 13a of the fixing groove 13 toward the concave raceway are brought close to one plane so as to seal the seal. When internal pressure is applied to the member 5, the main lip 7 and the base portion 6 of the seal member 5 can be more reliably brought into contact with the surface.

  Since the thickness t1 of the main lip 7 is provided thinner than the radial thickness t2 of the seal body 11 of the base 6, the seal torque of the main lip 7 can be reduced, and the seal member 5 has an internal thickness. When pressure is applied, the main lip 7 can be positively elastically deformed. As a result, the main lip 7 is surely pressed against the seal sliding side inclined portion 16a of the annular projection 16 of the concave raceway ring, so that the base 6 is less likely to be caught with respect to the annular wall portion 14. However, it is possible to prevent the seal member 5 from coming out on the base 6 side.

  Since the seal member 5 includes the auxiliary lip 8 in contact with the end surface 2d of the outer ring 2, the auxiliary lip 8 can further maintain the sealing performance of the seal member 5 and prevent grease leakage from the bearing space 4. Since the secondary lip 8 is in axial contact, the sealing torque can be reduced more than the lip portion in radial contact.

As another example of the seal structure, as shown in FIG. 3, among the base portion 6 of the seal member 5, the base inner side surface 6 a facing the bottom of the annular groove 12 has a plurality of intersection angles α2 of 90 degrees or more and 180 degrees or less. It is good also as the shape connected by the surface (two surfaces in the example of FIG. 3). The “intersection angle” α2 refers to an angle viewed from the inside of the seal member 5. In this case, the rigidity of the base 6 of the seal member 5 can be increased and local deformation can be prevented.
As shown in FIG. 4, the bottom surface 12 a of the fitting groove of the seal base 6 may be brought into contact with the seal base 6. As shown in FIG. 5, the bearing space side groove side surface 12 b of the seal base 6 and the seal base 6 are connected. You may make it contact. In this example, the bottom surface 12 a is the bottom surface of the annular groove 12 provided on the outer peripheral surface of the inner ring 1, and the bearing space side groove side surface 12 b is the inner side in the axial direction at the bottom of the annular groove 12 provided on the outer peripheral surface of the inner ring 1. It is the inside surface. As shown in FIG. 6, the bottom surface 12 a and the bearing space side groove side surface 12 b of the fitting groove may be brought into contact with the seal base 6. 4 to 6, the coefficient of friction increases, the fixation of the seal base 6 can be stabilized, and the suppression of grease leakage from the fixed part can be enhanced. Further, since the tightness of the seal lip can be maintained, the sealing performance can be stabilized.

  4 and 5 show an example of a wind turbine for wind power generation. This windmill 21 is provided with a nacelle 23 on a support base 22 so as to be able to turn horizontally, and a main shaft 25 is rotatably supported in a casing 24 of the nacelle 23. A blade 26 which is a wing is attached. The other end of the main shaft 25 is connected to the speed increaser 27, and the output shaft 28 of the speed increaser 27 is coupled to the rotor shaft of the generator 29.

  The nacelle 23 is rotatably supported by the slewing bearing BR1. In the slewing bearing of any of the embodiments, for example, a slewing bearing BR1 for the nacelle 23 having a gear or the like provided on the outer peripheral surface of the outer ring 2 is used. As shown in FIG. 4, a plurality of drive sources 30 are installed in the casing 24, and a pinion gear is fixed to each drive source 30 via a speed reducer (not shown). It arrange | positions so that the said gear of the outer ring | wheel 2 (FIG. 1) may mesh | engage with the said pinion gear. For example, the outer ring 2 is connected and fixed to the support base 22 by a plurality of through holes 2 b, and the inner ring 1 is fixed to the casing 24. The plurality of drive sources 30 are driven in synchronization, and this turning driving force is transmitted to the outer ring 2. Therefore, the nacelle 23 can turn relative to the support base 22.

  The blade 26 is rotatably supported by the swing bearing BR2. As this slewing bearing BR2, in the slewing bearing of any of the embodiments, for example, a bearing provided with a gear on the inner peripheral surface of the inner ring 1 is applied. A driving source for rotating the blade 26 is provided at the protruding end portion 25 a of the main shaft 25. The outer ring 2 of the slewing bearing is connected and fixed to the distal end portion 25a, and a gear attached to the inner peripheral surface of the inner ring 1 is engaged with a pinion gear of the drive source. The blade 26 can turn by driving the driving source and transmitting the turning driving force to the inner ring. Therefore, the slewing bearing BR2 can support the wind turbine blade 26 with respect to the main shaft 25 so as to be rotatable about an axis L2 substantially perpendicular to the main shaft axis L1. In this way, the angle of the blade 26 and the direction of the nacelle 23 can be changed at any time according to the wind condition.

  When the slewing bearing having any one of the above seal structures is used in a wind turbine for wind power generation, it is possible to prevent the lip portion 9 of the seal member 5 from being reversed and the seal member 5 from falling off when the internal pressure is increased. As a result, the sealing performance of the seal member 5 can be maintained and grease leakage can be prevented, so that the surrounding environment can be protected and the bearing life can be extended. Further, since the sealing torque can be reduced, it is not necessary to increase the capacity of the turning torque. Therefore, it is possible to reduce the size of the drive source and reduce the manufacturing cost.

These slewing bearings are used to slew various machines used outdoors or indoors, such as hydraulic excavators other than those for wind power generation, construction machines such as cranes, rotary tables for machine tools, gun seats, parabolic antennas, and lifting machines. It can also be applied to parts.
The slewing bearing may be one in which the inner and outer rings have double-row raceway grooves or a cylindrical roller type (three-row cylindrical roller, cross roller).

DESCRIPTION OF SYMBOLS 1 ... Inner ring 2 ... Outer ring 1a, 2a ... Track groove 2c ... Seal sliding contact surface part 4 ... Bearing space 5 ... Seal member 6 ... Base part 6a ... Base inner side surface 7 ... Main lip 7a ... Axial inner side surface 8 ... Sub lip 9 ... Lip part 10a ... Insertion groove 12 ... Annular groove 13 ... Fixed groove 13a ... Seal fixing side inclined part 14 ... Annular wall part 16 ... Annular protrusion 16a ... Seal sliding side inclined part 23 ... Nacelle 26 ... Blades BR1, BR2 ... Slewing bearing

Claims (13)

A raceway groove is formed in each of the races of the inner ring and the outer ring, a plurality of rolling elements are provided between the raceway grooves of the inner and outer rings, and a step which becomes uneven between the inner and outer rings is provided at the axial end of the inner and outer rings. In the seal structure of the slewing bearing provided with the seal member made of an elastic body that seals the axial ends of the inner and outer rings having the step,
The seal member includes a base fixed to a portion protruding from the concave raceway of the convex raceway that is the convex side of the step, and one or more that are in contact with the concave raceway that is the concave side of the step. A lip portion, and one of the lip portions includes a main lip that extends in an inclined manner so as to be located on the inner side in the axial direction of the bearing space toward the tip.
Provided on the peripheral surface of the concave raceway on the bearing space side is a seal slidable contact portion for slidingly contacting the main lip of the seal member, and on the end side of the peripheral surface of the concave raceway than the seal slidable contact portion. The annular projecting portion projecting in the radial direction is provided, and the seal sliding side inclined portion is disposed on the inner surface in the axial direction of the annular projecting portion so as to be located on the outer side in the axial direction toward the projecting tip.
An annular groove is provided on the peripheral surface of the convex raceway, and a fixing groove is provided on an outer surface in the axial direction at the bottom of the annular groove, and the base portion of the seal member includes the peripheral surface of the convex raceway and the circumferential surface. There is a groove for fitting into which the annular wall portion that is a portion between the inner surface of the fixed groove is fitted, and the groove side surface on the bearing space side of the inner surface of the fixed groove moves away from the bearing space toward the groove bottom side portion. A seal structure for a slewing bearing, wherein a seal fixing side inclined portion is provided to be inclined so as to be positioned on the side.   The base inner surface facing the bottom of the annular groove of the convex raceway ring in the base portion of the seal member according to claim 1 is connected with a single curved surface or a continuous curved surface having no inflection point. Slewing bearing seal structure.   In Claim 1, Of the base part of the said seal member, The shape which connected the inner surface of the base part which faces the bottom part of the said annular groove of the said convex side track ring with the several surface which has 90 degree or more and 180 degrees or less of intersection angles, Slewing bearing seal structure.   The seal structure for a slewing bearing according to claim 2 or 3, wherein an angle of an intersection line connecting the inner side surface in the axial direction of the main lip and the inner side surface of the base portion is 180 degrees or more and 270 degrees or less.   5. The surface according to claim 1, wherein a seal sliding side inclined portion of the annular projecting portion is extended to the convex raceway side, and the seal fixing side inclined portion of the fixing groove is a concave side track. A seal structure for a slewing bearing provided with a seal sliding side inclined portion and a seal fixing side inclined portion so that a surface extended to the ring side intersects.   6. The seal structure for a slewing bearing according to claim 1, wherein the main lip is thinner than a base portion.   7. The seal structure for a slewing bearing according to claim 1, wherein the bottom surface of the fitting groove or the bearing space side groove side surface of the seal base and the seal base are brought into contact with each other.   8. The seal structure for a slewing bearing according to claim 1, wherein the seal member is made of nitrile or chloroprene.   9. The slewing bearing according to claim 1, wherein the seal member includes, as one of the lip portions, a sub lip that branches from the base portion separately from the main lip and contacts the end surface of the concave raceway ring. Seal structure.   10. The seal structure for a slewing bearing according to claim 1, wherein an initial tightening margin of the main lip is 2 mm or more and 6 mm or less.   A slewing bearing to which the seal structure according to any one of claims 1 to 10 is applied.   12. The slewing bearing according to claim 11, wherein the blade of the wind turbine is supported so as to be rotatable about an axis substantially perpendicular to the spindle axis with respect to the spindle.   The slewing bearing according to claim 11, wherein the nacelle of the wind turbine is slidably supported with respect to the support base.

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